Process for obtaining methyl tert-butyl ether and premium-grade fuel from butanes and/or C4 cuts originating from catalytic cracking or reforming

摘要

Process for obtaining methyl tert-butyl ether and a premium-grade petrol from a C4 hydrocarbon cut originating from a catalytic reforming or cracking unit, in which the feedstock is subjected to a dehydrogenation reaction in a zone 7, the effluent originating from the zone 7 is fractionated in the columns 10 and 15 and the light gas containing hydrogen is recycled via the conduits 11, 12 and 34 towards the zone 7, a gaseous mixture containing chiefly propane is drawn off via the conduit 16 and the remainder of the effluent is conveyed via the conduit 17 to the etherification section 18; the effluent from etherification is fractionated (columns 21 and 25) into methanol, which is recycled (conduits 22 and 29) with fresh methanol entering via the conduit 23 into the etherification zone, and into methyl tert-butyl ether (conduit 26) and a hydrocarbon fraction (conduit 27) which is conveyed into an alkylation section 28; the effluent from alkylation is fractionated in the column 31 into an n-butane-isobutane fraction (conduit 33), which is recycled to the dehydrogenation zone 7, and into an alkylate (conduit 32) forming a premium-grade petrol cut. The by-products from the effluent from alkylation are drawn off via the conduit 29. …IMAGE…